Securing a match for a bone marrow transplant to treat a cancer patient can be difficult enough, but it is not all smooth sailing from that point either. Preparing a donor's stem cells for harvesting involves a lot of time and injections of growth factor to boost stem cell populations ahead of the procedure. But Australian scientists have now unearthed a more direct route, discovering a new molecule that entices an adequate number of stem cells out into the blood stream to make for a much easier, swifter collection.

Doses of chemotherapy to treat cancers like leukaemia can kill of the body's bone marrow, the soft substance inside the bone cavity behind the production of blood cells. Pulling bone marrow cells from a healthy donor and transferring them into the patient can restore their ability to generate blood cells, but this doesn't come without its complications.

Taking these stem cells from the blood rather than the bone marrow is one way to increase the chances of success, because here they are easier to collect and in greater abundance. This technique involves the use of mobilizing agents, molecules that usher the stem cells from the bone marrow into the blood stream for harvesting, though so far these have only worked when used in combination with a growth factor.

But scientists at Australia's Commonwealth Scientific and Industrial Research Organisation (CSIRO) and the Australian Regenerative Medicine Institute have now discovered a new molecule that rules out the need for a growth factor altogether. The researchers demonstrated that combining a newly-discovered molecule called BOP with one mobilizer already in use called AMD3100, enabled the stem cells to become visible in the blood within an hour of a single dose.

"Current treatment requires the donor to have growth factor injections for several days leading up to the procedure," says CSIRO's Dr Susie Nilsson. "Using the new method eliminates the need for this, meaning a procedure that once took days can be reduced to around an hour."

In their pre-clinical studies, the researchers found no evidence of side effects and that once transplanted, the harvested cells replenished the entire bone marrow system. They say it will lead to stem cell harvesting that is more efficient and effective by minimizing the stress for donors and, in turn, the patients as well. The team will next look to assess the combination of the BOP molecule with the growth factor in phase 1 human trials, and then eventually BOP and AMD3100 molecules combined.

The research was published in the journal Nature Communications.

Source: CSIRO

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